初二几道数学分式

问题描述:

初二几道数学分式
(1)(m²-3m)/9-m²
(2)(3a²-ab)/(9a²-6ab+b²),其中a=3/4,b=-2/3
(3)(a²-b²)/(a²+ab)
(4)(a²+ab)/(a²+2ab+b²)
拜托速度T T

(1)(m²-3m)/9-m²=m(m-3)/(3+m)(3-m)=-m/(m+3)(2)(3a²-ab)/(9a²-6ab+b²)=a(3a-b)/(3a-b)²=a/(3a-b)=9/35(3)(a²-b²)/(a²+ab)=(a+b)(a-b)/a(a+b)=(a-b)/a(4...